Spergualin is an antibiotic produced by microorganisms belonging to the genus Bacillus and many related compounds thereof have been synthesized.
Among the spergualin and its related compounds which have been already known, highly active compounds are poor in chemical stability, while chemically stable compounds are poor in activity. Therefore, it is expected to develop spergualin-related compounds which are chemically stable and highly active and yet has a low toxicity.